Calcium chloride might contain bromine

[JasonLion]

This post asked about bromine in calcium chloride.

If purchasing calcium chloride, be sure that it is pure enough for pool use. Some manufacturers have started allowing bromine in their calcium chloride, which is not good for chlorine pools.

Note: The quote was taken slightly out of context. I was only referring to calcium chloride sold as a deicer. The sticky the quote was taken from has been changed to clarify this.

Where in the world did you copy that information? There is NO reason to add bromine to calcium chloride! (I assume that the person who wrote that was referring to sodium bromide). If you add bromides to a chlorine pool it will convert it to a bromine pool until the sun and additional chlorine burn off the bromine.
I suspect that whoever wrote that didn't really know what they were talking about!

Calcium chloride sold as a deicer tends to have some bromine in it because there is bromine in the brine that calcium chloride is manufactured from and Dow decided to stop taking it out, see this statement from Dow. Dow is the primary supplier of calcium chloride in the US. Food grade calcium chloride is fine, but it is difficult to find at the consumer level.

Any calcium product sold for pool use will have been made from food grade materials and will be fine. For pool use you will normally find calcium chloride dihydrate, not calcium chloride.

 

[Guest]

Calcium chloride sold as a deicer tends to have some bromine in it because there is bromine in the brine that calcium chloride is manufactured from and Dow decided to stop taking it out, see this statement from Dow. Dow is the primary supplier of calcium chloride in the US. Food grade calcium chloride is fine, but it is difficult to find at the consumer level.

Any calcium product sold for pool use will have been made from food grade materials and will be fine. For pool use you will normally find calcium chloride dihydrate, not calcium chloride.

According to the statement from dow the solid food grade calcium chloride has more bromine in it than the DowFlake and Peladow. The LIQUID food grade calcium has a lower amount of bromine.

 

[JasonLion]

You are right, food grade is not the solution. Besides, consumers don't have any way to purchase food grade calcium chloride. They only things that are readily available are the deicer product and swimming pool calcium increaser. I am simply assuming that manufacturers of swimming pool calcium increaser products use calcium chloride with the bromine removed one way or another.

Dow had another statement, which I can't find right now, that specifically said that DowFlake would suppress chlorine levels in swimming pools. My understanding is that the effect is similar to what the bromine based mustard algae fighting products do. The chlorine goes into activating the bromine and so gets rapidly consumed, but that with sunlight, plenty of chlorine, and a couple of days the bromine will dissipate and you will have a chlorine pool again. DowFlake is typically much cheaper than swimming pool calcium increaser, but given that hassle and expense it is probably simpler to just purchase swimming pool calcium.

 

[JasonLion]

Moved from another thread. JasonLion

The amount of bromine in DowFlake is STILL inconsequential It amonts to ony .7% of the weight of the product according to Dow literature. (.82% for Peladow)
These products have LESS bromine in them than the food grade Calcium Chloride in solid form that Dow makes.
Dow published this statement:
http://www.dow.com/PublishedLiterature/dh_0066/0901b80380066be8.pdf?filepath=calcium/pdfs/noreg/173-01748.pdf&fromPage=GetDoc
IF one raised the calcium level 100 ppm in 10kgallons with Dowflake you would only be adding less than 1.4 oz of bromine into 10K gallons of water. This amount is really inconsequential.
For Peladow this would be just slightly over 1.2 oz of bromine.
When you consider that this small amount of bromine will be quickly destroyed it really doesn't seem to matter. Remember that 1 oz of sodium bromide per 200 gallons is what is normally added to a bromine spa on startup.
Also consider that 6 oz sodium bromide per 10000 gallons is what is normally used as a mustard algae treatment in such products as Jack's Yellow Stuff, Proteam Mustard and Black Magic, and most of the United Chemical range of products. This higher level of bromine is actually short lived in the water, it's quicky broken down by the chlorine andsunlight. The caution on bromate formation is real but this is mostly a problem in bromine spas with ozonators.

 

[JasonLion]

Alright, given that, how about this write up:

You increase CH with calcium chloride, sold as a deicer, or calcium chloride dihydrate, sold by pools stores for increasing calcium. You lower calcium by replacing water. In a spa with an ozone system you should only use calcium products sold for spa use because of possible interactions between the ozone and impurities in bulk calcium chloride.

 

[Guest]

Alright, given that, how about this write up:

You increase CH with calcium chloride, sold as a deicer, or calcium chloride dihydrate, sold by pools stores for increasing calcium. You lower calcium by replacing water. In a spa with an ozone system you should only use calcium products sold for spa use because of possible interactions between the ozone and impurities in bulk calcium chloride.

Moot point if the spa is a bromine one with an ozonator since MUCH more sodium bromide is going into the spa at start up than the calcium would add!!!Bromates can form in any bromine spa with an ozonator. They are a suspected carcinogen in drinking water but, as we all know, many of the complaints concering the safety of chlorine are from drinking water sanitation and not applicable to pools, particularly outdoor ones. I think Dow just had to publish that to cover their assets, so to speak :angel:
I suspect that much of the calcium being sold for pool/spa use is STILL Dowflake and Peledow. However, the 50 lb bags we have been getting from our distrubutor at work for the past 8 months have not been Dowflake anymore but Tetra . I will have to look on the bag for the level of bromine in it since they give a breakdown of the purity. It might be nothing more than repackaged Peladow or it might be a purer calcium pellet.

 

[Mr NaCly]

There are a few misleading and incorrect statements in this post that need to be corrected for the record.

With regards to bromide levels in Dow's calcium chloride, a few years ago Dow changed the source of their brine from which calcium chloride is manufactured. In that shift, they exited a market that used the bromide previously found in their original brine source.

The discussions here have addressed the bromide in the current calcium chloride which the writer has linked an October 2006 technical bulletin as the source of the information on this level. Realize that this manufacturing change took place in 2007, and this document "anticipates" levels to "be in the range of", but this is not a guarantee.

The brine from which Occidental Chemical's (formerly DOW) calcium chloride is made is a natural brine pulled from the Manistee, MI region by Martin Marietta who manufacture magnesium based products and then send the co-product stream on to Dow in Ludington, MI by pipeline for manufacturing into CaCl2. Realize that as with ALL mined products, spikes of various elements are common. What this means to the pool chemistry aficionado is that while this EARLY document discusses projected AVERAGE expectations, it does carefully avoid the thing those of us in the business know all too well: spikes happen.

So the linked document projects what they expect will be average bromide levels in range of 6,000 to 8,500 ppm Br, they do not caution users that spikes can and do happen. In fact, spikes are how averages are determined.

If the average depth of your pool is 5'3", the deep end might be 9' and the shallow end 3'. Operating on the expectations of Br levels as presented in these posts would be like telling the person who is 5'8" tall and can't swim to not worry about jumping in your pool because the average depth is less than their height. The problem here is obvious for the 5'8" non-swimmer in the 9' deep end.

The point is that averages are not absolutes and are by no means an assurance of a maximum level of Br in DOW calcium chloride. That information is available only in the form of a manufacturing specification on that particular element which is NOT a public document. Caveat emptor.

With regards to the statement that "Tetra" calcium is made by the same Tetra as the pool people; that is incorrect. They are not the same company at all and in fact, at this time a good portion of Tetra's liquid calcium chloride is coming from DOW so using Tetra calcium chloride may well be just jumping from one frying pan to another. Additionally, Tetra is constructing a new CaCl2 manufacturing plant in Magnolia AR where bromide levels in the brine are known to be high so when that product begins hitting the market, make sure you review the sales specifications and details before wondering why you can't seem to properly maintain Cl levels in your new pool.

There is no assurance of impurities in any product unless you have a certified statement of ingredients. In the chemical industry, this document is called a certificate of analysis and they are lot specific; tied to a specific batch of product identified by a lot number, or batch number, that is individually tested for the analytes stated within the C of A document. Whether or not Br is an analyte tested in food grade can only be determined by an examination of the C of A for the specific lot, or by review of the FG specifications in place.

If you act in reliance on average assurances, then you making decisions on a projected average and not on actual and in my line of work (chemicals) that is very dangerous. Work in absolutes to be sure.

I get frequent calls from pool owners who complain that they have seen high Br levels in their pools from unknown sources thinking it's coming from the CaCl2. It might be, but it also might not be. With any mined material you get spikes of impurities so be aware of this before jumping to conclusions, or more appropriately jumping into the deep end if you can't swim.
:blah:

The company I work for buys calcium chloride from all over the world and US and I can tell you with total conviction that while you want to trust vague assurances, they can only be trusted when they are in writing with specific guarantees.

While on the subject of calcium and hardness, understanding the Langelier Index is important so search and read on that if you find yourself in the chemical equivalent of a death spiral in your pool chemistry.

Hope this helps clear the pool water on this confusing topic.

 

[chem geek]

Welcome to TFP and thanks for the detailed info.

Even if one were to add 300 ppm of calcium chloride (normally there is already some CH in fill water, but even ignoring that), then in 10,000 gallons this is 444 ounces weight of Peladow or 588 ounces weight of Dowflake. Even if I use a spiked amount of 2% of the weight as bromine, so say 6 ounces, then that's about 4.5 ppm bromine roughly equivalent to around 2 ppm chlorine. Though not great, it isn't so high as to be something to cause a sustained "bromine pool" problem and the bromine will outgas over time.

It would be interesting to see if anyone notices a temporarily higher chlorine demand in an outdoor pool exposed to sunlight soon after adding a large amount of calcium chloride, say on a pool refill, and to see how long this condition lasts.

Richard

 

[JasonLion]

I was thinking about mentioning a possible short term increase in chlorine demand in the pool school article where it talks about calcium chloride. But no one has actually reported any problems, so it appears to be too rare to be worth worrying about.

 

[Guest]

I get frequent calls from pool owners who complain that they have seen high Br levels in their pools from unknown sources thinking it's coming from the CaCl2. It might be, but it also might not be. With any mined material you get spikes of impurities so be aware of this before jumping to conclusions, or more appropriately jumping into the deep end if you can't swim.
:blah:

Mr. Salty,
How do these pool owners determine that they have high bromine levels? Are they sanitizing with chlorine or bromine? Since there is no specific test for bromine (specifically either bromide or hypobromous acid) available to pool owners or even to professionals I really wonder how it can be determined whether chlorine or bromine is present since current chemical testing methods for pools/spas (OTO, DPD, FAS-DPD or syringaldazine/vanillin azine ) cannot differentiate between chlorine or bromine sanitizer levels in the water. To confuse matters more, if they are using a total chlorine/bromine test such as OTO or DPD3 then any oxidizer will show up on the test including other halogens, ozone, percarbonates, monopersulfate and peroxides. IF they are having laboratory analysis of their pool water done (whihc is highly doubtful) then that is a different matter but if they are doing that they can also have said analysis done on the CaCL2 to determine if it is the source of the bromide.